feat: model validation, calibration, and signal quality layer

- Migration 035: prediction_snapshots, prediction_outcomes, signal_evidence_links, model_metric_snapshots tables + SQL views
- Prediction snapshot writer with canonical evidence keys, duplicate detection, contribution scores
- Outcome evaluator across 5 horizons (1h, 6h, 1d, 7d, 30d)
- Metrics engine: ECE, Brier score, IC, Rank IC, benchmark comparison
- Attribution engine: per-source, per-catalyst, per-layer performance
- Calibration engine: Bayesian shrinkage source reliability
- Quality gate for live trading eligibility with configurable thresholds
- 7 new /api/validation/* endpoints
- Upgraded OpsModel dashboard with validation tab
- Enhanced recommendation display with calibration context
- Backtest replay validation mode
- 86 Python tests (unit + property-based), 179 frontend tests passing

frontend/src/api/hooks.ts

@@ -885,3 +885,169 @@ export function useToggleMacro() {
     onSuccess: () => qc.invalidateQueries({ queryKey: ['macro-status'] }),
   });
 }
+
+// ---------------------------------------------------------------------------
+// Validation: Model Quality & Calibration (Requirements 12.1, 12.2, 12.3, 12.7)
+// ---------------------------------------------------------------------------
+
+export interface ModelMetricSnapshot {
+  id: string;
+  generated_at: string;
+  lookback_window: string;
+  horizon: string;
+  prediction_count: number;
+  win_rate: number | null;
+  directional_accuracy: number | null;
+  information_coefficient: number | null;
+  rank_information_coefficient: number | null;
+  avg_return: number | null;
+  avg_excess_return_vs_spy: number | null;
+  avg_excess_return_vs_sector: number | null;
+  calibration_error: number | null;
+  brier_score: number | null;
+  buy_win_rate: number | null;
+  sell_win_rate: number | null;
+  hold_win_rate: number | null;
+  metadata: Record<string, unknown> | null;
+}
+
+export interface ValidationSummary {
+  snapshot: ModelMetricSnapshot | null;
+  gate_status: Record<string, unknown> | null;
+}
+
+export interface CalibrationBucket {
+  bucket_low: number;
+  bucket_high: number;
+  avg_confidence: number;
+  observed_win_rate: number;
+  prediction_count: number;
+  miscalibrated: boolean;
+}
+
+export interface ValidationCalibration {
+  buckets: CalibrationBucket[];
+  lookback: string;
+  horizon: string;
+}
+
+export interface ICByHorizonEntry {
+  horizon: string;
+  information_coefficient: number | null;
+  rank_information_coefficient: number | null;
+  prediction_count: number;
+  generated_at: string | null;
+}
+
+export interface ValidationICByHorizon {
+  horizons: ICByHorizonEntry[];
+  lookback: string;
+}
+
+export interface ValidationGateStatus {
+  gate_status: Record<string, unknown> | null;
+  updated_at?: string | null;
+  message?: string;
+}
+
+export function useValidationSummary(lookback = '30d', horizon = '7d') {
+  const qs = new URLSearchParams();
+  if (lookback) qs.set('lookback', lookback);
+  if (horizon) qs.set('horizon', horizon);
+  const path = `/api/validation/summary${qs.toString() ? '?' + qs : ''}`;
+  return useGet<ValidationSummary>(['validation-summary', lookback, horizon], 'query', path);
+}
+
+export function useValidationCalibration(lookback = '30d', horizon = '7d') {
+  const qs = new URLSearchParams();
+  if (lookback) qs.set('lookback', lookback);
+  if (horizon) qs.set('horizon', horizon);
+  const path = `/api/validation/calibration${qs.toString() ? '?' + qs : ''}`;
+  return useGet<ValidationCalibration>(['validation-calibration', lookback, horizon], 'query', path);
+}
+
+export function useValidationICByHorizon(lookback = '30d') {
+  const qs = new URLSearchParams();
+  if (lookback) qs.set('lookback', lookback);
+  const path = `/api/validation/ic-by-horizon${qs.toString() ? '?' + qs : ''}`;
+  return useGet<ValidationICByHorizon>(['validation-ic-by-horizon', lookback], 'query', path);
+}
+
+export function useValidationGateStatus() {
+  return useGet<ValidationGateStatus>(['validation-gate-status'], 'query', '/api/validation/gate-status');
+}
+
+// ---------------------------------------------------------------------------
+// Validation: Attribution — Sources, Catalysts, Layers (Requirements 12.4, 12.5, 12.6)
+// ---------------------------------------------------------------------------
+
+export interface SourceAttribution {
+  source: string;
+  source_type: string;
+  prediction_count: number;
+  avg_weight: number;
+  avg_contribution_score: number;
+  win_rate: number;
+  avg_future_return: number;
+  avg_excess_return_vs_spy: number;
+  information_coefficient: number | null;
+  duplicate_rate: number;
+}
+
+export interface SourceAttributionResponse {
+  sources: SourceAttribution[];
+  lookback: string;
+  horizon: string;
+}
+
+export interface CatalystAttribution {
+  catalyst_type: string;
+  prediction_count: number;
+  win_rate: number;
+  avg_future_return: number;
+  avg_excess_return_vs_spy: number;
+  information_coefficient: number | null;
+}
+
+export interface CatalystAttributionResponse {
+  catalysts: CatalystAttribution[];
+  lookback: string;
+  horizon: string;
+}
+
+export interface LayerAttribution {
+  layer: string;
+  avg_contribution_pct: number;
+  dominant_win_rate: number;
+  dominant_ic: number | null;
+}
+
+export interface LayerAttributionResponse {
+  layers: LayerAttribution[];
+  lookback: string;
+  horizon: string;
+}
+
+export function useValidationAttributionSources(lookback = '30d', horizon = '7d') {
+  const qs = new URLSearchParams();
+  if (lookback) qs.set('lookback', lookback);
+  if (horizon) qs.set('horizon', horizon);
+  const path = `/api/validation/attribution/sources${qs.toString() ? '?' + qs : ''}`;
+  return useGet<SourceAttributionResponse>(['validation-attribution-sources', lookback, horizon], 'query', path);
+}
+
+export function useValidationAttributionCatalysts(lookback = '30d', horizon = '7d') {
+  const qs = new URLSearchParams();
+  if (lookback) qs.set('lookback', lookback);
+  if (horizon) qs.set('horizon', horizon);
+  const path = `/api/validation/attribution/catalysts${qs.toString() ? '?' + qs : ''}`;
+  return useGet<CatalystAttributionResponse>(['validation-attribution-catalysts', lookback, horizon], 'query', path);
+}
+
+export function useValidationAttributionLayers(lookback = '30d', horizon = '7d') {
+  const qs = new URLSearchParams();
+  if (lookback) qs.set('lookback', lookback);
+  if (horizon) qs.set('horizon', horizon);
+  const path = `/api/validation/attribution/layers${qs.toString() ? '?' + qs : ''}`;
+  return useGet<LayerAttributionResponse>(['validation-attribution-layers', lookback, horizon], 'query', path);
+}